Cluster Elements

Purpose:

In a standard network, each element is assigned a unique Primary Node Identifier (PNI), which is used to route calls between the elements. In a cluster, however, each element shares the same PNI. Calls are routed between elements using the Cluster Element Identifier (CEID) instead of the PNI.

In the Cluster Elements form, you must assign each cluster element a unique 1- to 7-digit CEID. The Cluster Elements form of each element lists its own CEID as "local" and also lists the CEIDs of all other cluster elements in the Cluster Element ID Digits column. Aside from that column, the Cluster Elements form of each cluster element displays the same information.

Select "Yes" in the local element column to assign a CEID digit string to the local cluster element. For the remote cluster elements, the CEID index associates a CEID string in the Cluster Elements form with remote directory numbers in the Remote Directory Numbers form.

The CEID digit strings of the remote elements must translate into an ARS route, list, or plan, to the corresponding remote element. For example, for the CEID digit string, 7167, any one of the following ARS entries in the ARS Digits Dialed form will satisfy the requirement for a corresponding ARS entry:

Digits Dialed	Number of Digits to Follow	Termination Type	Termination Number
7167	+4	Route	7
7167YYYY	+0	List	5
7167NXY	+ unknown	Plan	2

As a further example, the following ARS entries will NOT satisfy the requirement:

Digits Dialed	Number of Digits to Follow	Termination Type	Termination Number
7	+7	Route	7
71YYYYYY	+0	List	5
7167NXY5	+ unknown	Plan	2

The Cluster Elements form is divided into two sections:

Cluster Elements (top section): provides a "Create Cluster" button that allows you to create a cluster to which to add elements. After a cluster has been created, this section of the form will allow you to change the name and PNI of the cluster.
Cluster Members information (lower section): allows you to modify an existing cluster. You can Add Member, Change Member, Change Page Member, Change All Members, or Delete Member.

You also use the Cluster Elements form to associate each CEID digit string with a CEID index. The CEID index is assigned to directory numbers in the Remote Directory Numbers form. Assigning a directory number with the CEID index of a remote element classifies that directory number as a remote directory number on that element. When a user on element A dials the remote directory number of an extension on element B, element A automatically inserts the CEID digit string of element B in front of the dialed directory number. ARS then routes the call to the remote extension based on the CEID digits. The user does not dial the CEID digits to call a remote directory number.

ARS Wild Cards

ARS wild cards can be used in clustered environments, to replace explicitly-defined CEID trailing digits. For example, any of the following ARS rules can be used to define routes involving CEIDs in the ARS Digits Dialed form:

Digits Dialed	Number of Digits to Follow	Termination Type	Termination Number
167	3	Route	4
167NXYNXY	3	Route	5
167NNNNN	Unknown	Route	9

Use this form when performing the following tasks:

Adding Cluster Elements (for System Data Synchronization)
Data Sharing in a Multi-Clustered Network (for System Data Synchronization)

For more information:

Conditions

You can only add cluster elements to a cluster that has already been created.
If you are creating a new cluster, the local network element is added to the new cluster by default. You cannot create a cluster without including the local element in that cluster.
After modifying the PNI of a cluster, you must wait at least 15 minutes before you perform a sync operation; otherwise, the sync operation may fail.

Field Descriptions

Parameter	Description	Default Value
Cluster Elements
Name	Enter a unique name of up to nine characters for the cluster. The name must start with an upper case letter; enter all other letters in lower case. Digits are allowed but not spaces or non-alpha characters. A name is optional. If entered, the name is automatically added to the Network Elements form. Note: The name must be identical to the element name entered in Enterprise Manager. Otherwise, attempts by Enterprise Manager to program resilient data on the secondary controller will fail.	Blank
Primary Node ID (PNI)	The Primary Node ID is used to route calls to other non-cluster elements in the network. Clustered elements must share the same PNI. Enter a Primary Node ID for the cluster of up to 7 digits in length if the cluster is connected in a MSDN/DPNSS network. If the cluster does not belong to a MSNN/DPNSS network, a Primary Node ID is not required. A PNI cannot appear as a directory number or as an ARS string on any of the systems in the network. Use the Locate Number maintenance command to determine if the PNI is a number that is already used on any of the other elements in the network. This value also appears in the primary Directory Number (DN) field of the ARS Node Identities form. Note: A confirmation dialog displays for a PNI change if the PNI change will be distributed to other cluster members via the System Data Synchronization feature.	Blank
Cluster Members
Name	Enter the name of the cluster element. You can also enter the name from the Network Elements.	Blank
Cluster Element ID	Enter a unique (within the form) Cluster Element Identifier (CEID) Index. The CEID Index number associates a CEID digit string in the Cluster Elements form with remote directory numbers in the Remote Directory Numbers form. The numbers can be in the range of 1 to 999. If you enter a CEID index, you must enter a corresponding CEID digit string before you can commit the form. Before you can delete a CEID index, you must delete all references to remote telephone directory entries that are associated with that CEID index. Note: In a clustered, a redirect, or a resilient environment the PBX Number, defined in the ICP/PBX Networking form, must match the CEID Index Number.	Blank
Cluster Element ID Digits	Enter a CEID digit string. Assign unique CEID digit strings to each cluster element. In a network that is configured for the Voice Clustering (Portable Directory Number) feature, the CEID digit string allows calls to be routed between elements in the network. The CEID digit strings for remote elements must translate to a programmed ARS route, list, or plan for correct call routing. The CEID digit string can be 1 to 7 digits in length. If the ARS digits are not yet assigned, the field displays "Not assigned". Note: If you enter a CEID digit string, you must enter a corresponding CEID index before you can commit the form. Having remote CEID digit strings translate to at least one ARS route, route list, or plan with identical leading digits is recommended. By having identical leading digits you minimize the risk of dialing conflicts that result when CEID digits match a local DN, but requires that you program an explicit ARS entry for every node in the cluster. Notes: To facilitate the configuration of a large multi-hub cluster which uses transit nodes to route calls between nodes in the hubs, any digit string is allowed provided that it translates to a valid ARS route, route list, or route plan. This allows you to use ARS entries containing wildcards for cluster routing. For example, for three remote nodes with CEID digits 1#100, 1#200, and 1#300, all calls can be routed to the transit node (1#100) by the ARS entry 1# with unknown digits to follow. ARS routing digits for all cluster elements must be the same length for resiliency to work.	Blank
Local	Select "Yes" to assign the adjacent CEID digit string to the local element (the system that you are currently programming). You can only designate one CEID digit string to the local element. The CEID digit string of the local element is added to the system number plan and must therefore be a unique directory number. Select "No" for the remote elements.	No
Comments	Enter the cluster element name, containing up to 20 characters. Note: The description in the text field is not verified.	Blank
Feature DN	For the local element ("Local" is set to "Yes") enter a feature directory number. For a remote element, enter the feature directory number that corresponds to the local feature directory number of the remote element within the cluster. The local and remote feature directory numbers must be unique within the cluster and can be 1 to 7 digits in length. The directory number length must match the extension number length. Notes: This field allows DPNSS features such as busy lamp field messaging, direct paging, group page, and call pickup to function across the cluster. Do not use # or * in the Feature DN number because they can cause networking problems between the elements. If you leave this field blank, a negotiation failure may cause a virtual channel to be busied out every 20 seconds. When all virtual channels are busy, no IP trunks can be established with the indication of "XNET Busy".	Blank